Replacing fuel lines breva 1200 2008

Hi, bit of feedback appreciated. Need to source some small gauge(7 mm outer 5 mm inner) black fuel piping (about 1.5 metre)and tee connection if possible. Also how do you shrink the fuel line into the injectors, t piece and tank valve?? My old piping failed, fitted new suitable (I thought)piping using O clips only for that to fail and change color!
Thanks Howard